240 CHINESE ECONOMIC TEEES 



property used in medicine as a cathartic. Other species yield dyes. R. 

 frangula Linnaeus, native of Europe, N. Africa, W. Asia & Siberia, yields 

 a wood that makes a fine grade of charcoal for the manufacture of gun- 

 powder. With rare exceptions the genus is shrubby, and is of ornamental 

 interest only. 



Rhamnus carlhartica is a favorite hedge plant in Europe. 



Rhamnus davuricuS (Maxim.) Pallas. 

 (E. cathartica var dahurica Maximowicz.) 



A large spiny shrub or small tree up to 10 m. tall. Winter buds 

 scaly. Branchlets stout, thorny and glabrous. Leaves opposite, oblong- 

 elliptic, acuminate, crenate-serrate, tapering toward the base, coriaceous, 

 glabrous and gray-green beneath, 5-10 cm. long. Flowers in few-flowered 

 clusters, petals usually 4 (sometimes 5 or wanting). Fruit black, about 

 8 mm. in diameter. 



Amurland to N. China. 



Rhamnus utilis Decaisne. 



A shrub closely allied to the above. The leaves yield a green dye. 

 Widely distributed from Szechuan to Chekiang. 



Rhamnus crenatus Siebold & Zuccarini. 



Shrub 3 m. tall. Winter buds naked. Branchlets and young leaves 

 brownish pubescent ; leaves long acuminate, 5-10 cm. Flowers umbellate, 

 petals 5; peduncles shorter than the petioles. Fruit changing from red 

 to blue-black. 



Hupeh, Szechuan, Kiangsi, Chekiang to Fukien. 



ZIZIPHUS 



Deciduous or evergreen shrubs or trees. Branches rounded, armed 

 with usually unequal spines, one straight and the other curved. The 

 spines are modified stipules. Leaves alternate, entire or serrate, usually 

 appearing 2 ranked, firm, 3-5 nerved at the base, short petioled. Flowers 

 small greenish or whitish, pentamerous, in axillary cymes. Ovary 

 usually 2 (2-4) celled, free from the disk lining the calyx tubes; style 

 usually bifid. Fruit a drupe with 1-3 celled stone. 



